flock vs great deal

flock and great deal both are nouns.

Word	Noun	Adjective	Verb	Adverb
flock	Yes	No	Yes	No
great deal	Yes	No	No	No

As nouns, flock and great deal are synonyms defined as:

flock and great deal: (often followed by `of') a large number or amount or extent

flock (noun)	great deal (noun)
a group of birds	(often followed by `of') a large number or amount or extent
a group of sheep or goats
a church congregation guided by a pastor
an orderly crowd
(often followed by `of') a large number or amount or extent

flock (verb)	great deal (verb)
come together as in a cluster or flock
move as a crowd or in a group